Admixture situations of improved cultivars and their parental cultivars among Japanese accessions used in this study.

F1 progeny of ‘Yabukita’ from crosses (A) and natural crosses (B). F2 progeny of ‘Yabukita’ (C). These cultivars were derived from crosses between other parent materials different from ‘Yabukita’ (D). Different colors represent five ancestral components at K = 5 in structure analysis of Japanese var. sinensis. Light blue indicates the ‘Yabukita’-type ancestral component. The cultivars names of ‘Yabukita’ pedigree indicates red font.